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                                                                   EXHIBIT 4.15





                       ASSIGNMENT AND ASSUMPTION AGREEMENT

                                       to

                      AMENDED AND RESTATED TRUST AGREEMENT

                                     between

                         AMERICAN MUTUAL HOLDING COMPANY

                                       and

                           AMERUS LIFE HOLDINGS, INC.












                            Dated September 20, 2000





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                       ASSIGNMENT AND ASSUMPTION AGREEMENT

     This ASSIGNMENT AND ASSUMPTION AGREEMENT ("Agreement"), dated the 20th day
of September, 2000, is entered into by and between AMERICAN MUTUAL HOLDING
COMPANY, an Iowa mutual insurance holding company ("AMHC") and AMERUS LIFE
HOLDINGS, INC., an Iowa insurance holding company, ("AmerUs"). Capitalized terms
used herein without definition shall have the meanings assigned to such terms in
the Trust Agreement (as defined below).

                                   WITNESSETH:

     WHEREAS, AmerUs and Wilmington Trust Company, a banking corporation duly
organized and existing under the laws of Delaware, as trustee (the "Property
Trustee"), entered into a Trust Agreement, dated as of October 4, 1996 (the
"Original Trust Agreement"), to establish a business trust pursuant to the
Delaware Business Trust Act;

     WHEREAS, AmerUs, the Property Trustee, the Administrative Trustees named
therein, and several Holders as defined therein entered into an Amended and
Restated Trust Agreement (the "Trust Agreement"), dated as of February 3, 1997,
to provide for, among other provisions, the issuance and sale of the Capital
Securities by the Trust pursuant to the Underwriting Agreement;

     WHEREAS, AMHC has executed a Plan of Conversion, dated as of December 17,
1999, pursuant to which AMHC will convert from a mutual insurance holding
company into a stock holding company;

     WHEREAS, AMHC and AmerUs have entered into an Agreement and Plan of Merger,
dated December 17, 1999, pursuant to which the Depositor will merge with and
into AMHC, with AMHC as the surviving company (the "Merger");

     WHEREAS, AmerUs desires to assign and transfer its rights and obligations
under the Trust Agreement to AMHC;

     WHEREAS, AMHC desires to accept and acquire the rights and obligations of
AmerUs under the Trust Agreement;

     WHEREAS, this Assumption Agreement is being executed pursuant to Section
10.07 of the Trust Agreement; and

     WHEREAS, as required by Section 10.07 of the Trust Agreement, the Merger is
permitted under Article Eight of the Indenture.

     NOW, THEREFORE, the parties agree as follows:



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1.   Assignment. Upon the execution of this Agreement by the parties hereto,
     AmerUs does hereby assign and transfer to AMHC all of AmerUs' rights and
     obligations under the Trust Agreement.

2.   Assumption. Upon the execution of this Agreement by the parties hereto,
     AMHC does hereby absolutely and irrevocably accept the foregoing assignment
     and hereby assumes to be solely responsible for and to perform, as
     successor, AmerUs' obligations under the Trust Agreement.

3.   Effectiveness. This Agreement shall become effective as of the Effective
     Time (as defined in the Agreement and Plan of Merger referred to above) of
     the Merger.

4.   Binding Effect; Assigns. This Agreement shall be binding upon, and shall
     enure to the benefit of, the parties hereto and their respective successors
     and assigns.

5.   Execution in Counterparts. This Agreement may be executed in two or more
     counterparts, each of which will be deemed to be an original, but all of
     which together will constitute one and the same agreement.

6.   Governing Law. This Agreement will be governed by and interpreted in
     accordance with the internal laws of the State of New York, without giving
     effect to principles of conflicts of laws.

     IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Agreement as of the date set forth above.


                                            AMERICAN MUTUAL HOLDING COMPANY

                                            By: /s/ Roger K. Brooks
                                                -------------------------------
                                                Name:  Roger K. Brooks
                                                Title: Chairman, President and
                                                       Chief Executive Officer


                                            AMERUS LIFE HOLDINGS, INC.


                                            By: /s/ Roger K. Brooks
                                                -------------------------------
                                                Name:  Roger K. Brooks
                                                Title: Chairman, President and
                                                       Chief Executive Officer